Chromatography Forum

UV spect show an abs at around 220nm. Is this a kind of impurity to be related to organic aromatic cmpd? If yes, how can I detect this using GC-MS. Can someone share experience. Plus, USP method for chromatographic system uses water as solvent. Will like to try to avoid that. Can someone advice other literature that I can refer to?

The best source of information is the source of your glycerine.

Call the supplier and inform them of your findings. Ask them to explain the results and to inform you of the nature of the impurity.

If the problem is self caused you will save a lot of time. If the problem is vendor related then they will appreciate your informing them of the issue so they may correct it.

If it is a trace impurity and known to them, you will get good information and not hearsay. If not known to them they may help you determine the identity of the impurity quickly.

Good luck.

Thanks Mr. Chromatography, we are the supplier. We are just curious to check whether one of our glycerine could have contained traces other organic compound with one of our newer GC-MS.

I assume you do some wet chemistry tests to determine if aldehydes are present (or ketones or carboxylic acids or esters). These are the most likely contaminants with absorption of 220nm like you have detected with UV analysis. You can always try TLC to see if you can detect anything else. Have you derivitized glycerine to see if you can detect any other peaks by GC?

Sometimes using GC-MS is like using a microscope when you actually need wide angle binoculars.

Good luck.